88 research outputs found
The great global switch-off: international coverage in UK public service broadcasting
A new report by Polis, Oxfam and the International Broadcasting Trust (IBT)
An Early Beaker funerary monument at Porton Down, Wiltshire
Excavation of an Early Beaker-Early Bronze Age funerary monument at Porton Down revealed an unusually complex burial sequence of 12 individuals, spanning four centuries, including eight neonates or infants and only one probable male, surrounded by a segmented ring-ditch. In the centre was a large grave which contained the disturbed remains of an adult female, accompanied by a Beaker, which had probably been placed within a timber chamber and later ‘revisited’ on one or more occasions. This primary burial and an antler pick from the base of the ring-ditch provided identical Early Beaker radiocarbon dates. Two burials were accompanied by a Food Vessel and a miniature Collared Urn respectively, others were unaccompanied, and there was a single and a double cremation burial, both within inverted Collared Urns. A C-shaped enclosure nearby may have been contemporary with the funerary monument, but its date and function are uncertain. Other features included an Early Neolithic pit which contained a significant assemblage of worked flint, and several Middle Bronze Age ditches and a Late Bronze Age ‘Wessex Linear’ ditch that reflect later prehistoric land divisions probably related to stock control
VTXO: The Virtual Telescope for X-ray Observations
The Virtual Telescope for X-ray Observations (VTXO) will use lightweight Phase Frensel Lenses (PFLs) in a virtual X-ray telescope with 1 km focal length and with nearly 50 milli-arc second angular resolution. Laboratory characterization of PFLs have demonstrated near diffraction-limited angular resolution in the X-ray band, but they require long focal lengths to achieve this quality of imaging. VTXO is formed by using precision formation flying of two SmallSats: a smaller, 6U OpticsSat that houses the PFLs and navigation beacons while a larger, ESPA-class DetectorSat contains an X-ray camera, a charged-particle radiation monitor, a precision star tracker, and the propulsion for the formation flying. The baseline flight dynamics uses a highly-elliptical supersynchronous geostationary transfer orbit to allow the inertial formation to form and hold around the 90,000 km apogee for 10 hours of the 32.5-hour orbit with nearly a year mission lifetime. The guidance, navigation, and control (GN&C) for the formation flying uses standard CubeSat avionics packages, a precision star tracker, imaging beacons on the OpticsSat, and a radio ranging system that also serves as an inter-satellite communication link. VTXO’s fine angular resolution enables measuring the environments nearly an order of magnitude closer to the central engines of bright compact X-ray sources compared to the current state of the art. This X-ray imaging capability allows for the study of the effects of dust scattering nearer to the central objects such as Cyg X-3 and GX 5-1, for the search for jet structure nearer to the compact object in X-ray novae such as Cyg X-1and GRS 1915+105, and for the search for structure in the termination shock of in the Crab pulsar wind nebula. In this paper, the VTXO science performance, SmallSat and instrument designs, and mission description is described. The VTXO development was supported as one of the selected 2018 NASA Astrophysics SmallSat Study (AS3) missions
East Chisenbury Midden 2015−17: further investigations of the late prehistoric midden deposits, enclosure and associated settlement
After a gap of almost two decades further investigations were initiated at this remarkable late prehistoric midden
site, supported by Operation Nightingale/Breaking Ground Heritage. Geophysical survey clarified the extent of the
broadly contemporary enclosure surrounding the midden, as well as other related features, while subsequent excavations
provided new information on the midden, the enclosure and settlement. Two small trenches in the northeast half of the
midden revealed a different sequence and produced far fewer finds than the 1992−3 excavations in the southwest half,
demonstrating that it is not a homogeneous mound. A substantial ditch and associated bank, largely levelled by the late
Roman period, may have been contemporary with or pre-dated the early development of the midden, while some 150
postholes attested to the presence of numerous roundhouses and other structures within the enclosure. Overall, a date
range of c. 1000−500 cal. BC and possibly later is suggested from radiocarbon dating and pottery, the main phase of
midden development perhaps later than the majority of the settlement. Furthermore, recent results of radiocarbon dating of
material from the earlier excavations suggest the site sequence may continue as late as c. 400 cal. BC. Radiocarbon dating
of the few human remains has also highlighted the likelihood that some were curated, the probable intervals between the
dates of death and deposition ranging from a few decades to three centuries. Finds and environmental assemblages are
generally consistent with those previously found, but a few sherds of scratch cordoned bowl represent a significant new
discovery, as does a unique copper alloy ‘pendant’ of possible continental origin. Evidence now indicates that cattle, as well as sheep and pigs, were intensively managed and slaughtered on site, with the isotope data suggesting local origins for most of the animals, though some cattle may have been raised on pasturage further afield
Investigation of associations between retinal microvascular parameters and albuminuria in UK Biobank: a cross-sectional case-control study.
BACKGROUND: Associations between microvascular variation and chronic kidney disease (CKD) have been reported previously. Non-invasive retinal fundus imaging enables evaluation of the microvascular network and may offer insight to systemic risk associated with CKD. METHODS: Retinal microvascular parameters (fractal dimension [FD] - a measure of the complexity of the vascular network, tortuosity, and retinal arteriolar and venular calibre) were quantified from macula-centred fundus images using the Vessel Assessment and Measurement Platform for Images of the REtina (VAMPIRE) version 3.1 (VAMPIRE group, Universities of Dundee and Edinburgh, Scotland) and assessed for associations with renal damage in a case-control study nested within the multi-centre UK Biobank cohort study. Participants were designated cases or controls based on urinary albumin to creatinine ratio (ACR) thresholds. Participants with ACR ≥ 3 mg/mmol (ACR stages A2-A3) were characterised as cases, and those with an ACR < 3 mg/mmol (ACR stage A1) were categorised as controls. Participants were matched on age, sex and ethnic background. RESULTS: Lower FD (less extensive microvascular branching) was associated with a small increase in odds of albuminuria independent of blood pressure, diabetes and other potential confounding variables (odds ratio [OR] 1.18, 95% confidence interval [CI] 1.03-1.34 for arterioles and OR 1.24, CI 1.05-1.47 for venules). Measures of tortuosity or retinal arteriolar and venular calibre were not significantly associated with ACR. CONCLUSIONS: This study supports previously reported associations between retinal microvascular FD and other metabolic disturbances affecting the systemic vasculature. The association between retinal microvascular FD and albuminuria, independent of diabetes and blood pressure, may represent a useful indicator of systemic vascular damage associated with albuminuria
Associations between unilateral amblyopia in childhood and cardiometabolic disorders in adult life: a cross-sectional and longitudinal analysis of the UK Biobank
Background Amblyopia is a common neurodevelopmental condition and leading cause of childhood visual impairment. Given the known association between neurodevelopmental impairment and cardiometabolic dysfunction in
later life, we investigated whether children with amblyopia have increased risk of cardiometabolic disorders in adult
life.
Methods This was a cross-sectional and longitudinal analysis of 126,399 United Kingdom Biobank cohort participants
who underwent ocular examination. A subset of 67,321 of these received retinal imaging. Data analysis was
conducted between November 1st 2021 and October 15th 2022. Our primary objective was to investigate the
association between amblyopia and a number of components of metabolic syndrome and individual
cardiometabolic diseases. Childhood amblyopia, dichotomised as resolved or persisting by adulthood,
cardiometabolic disease and mortality were defined using ophthalmic assessment, self-reported, hospital
admissions and death records. Morphological features of the optic nerve and retinal vasculature and sublayers
were extracted from retinal photography and optical coherence tomography. Associations between amblyopia and
cardiometabolic disorders as well as retinal markers were investigated in multivariable-adjusted regression models.
Findings Individuals with persisting amblyopia (n = 2647) were more likely to be obese (adjusted odds ratio (95%
confidence interval): 1.16 (1.05; 1.28)), hypertensive (1.25 (1.13; 1.38)) and diabetic (1.29 (1.04; 1.59)) than individuals
without amblyopia (controls, (n = 18,481)). Amblyopia was also associated with an increased risk of myocardial
infarction (adjusted hazard ratio: 1.38 (1.11; 1.72)) and death (1.36 (1.15; 1.60)). On retinal imaging, amblyopic eyes
had significantly increased venular caliber (0.29 units (0.21; 0.36)), increased tortuosity (0.11 units (0.03; 0.19)), but
lower fractal dimension (−0.23 units (−0.30; −0.16)) and thinner ganglion cell-inner plexiform layer (mGC-IPL, −2.85
microns (−3.47; −2.22)). Unaffected fellow eyes of individuals with amblyopia also had significantly lower retinal
fractal dimension (−0.08 units (−0.15; −0.01)) and thinner mGC-IPL (−1.14 microns (−1.74; −0.54)). Amblyopic
eyes with a persisting visual deficit had smaller optic nerve disc height (−0.17 units (−0.25; −0.08)) and width
(−0.13 units (−0.21; −0.04)) compared to control eyes.
Interpretation Although further research is needed to understand the basis of the observed associations, healthcare
professionals should be cognisant of greater cardiometabolic dysfunction in adults who had childhood amblyopia.
Differences in retinal features in both the amblyopic eye and the unaffected non-amblyopic suggest generalised
versus local processes
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